1. Technical Field
The present invention relates to a plasma display panel, and more particularly, to a plasma display panel with an increased aperture ratio which improves luminous efficiency, and with increased discharge uniformity in a discharge space, thereby enhancing luminance.
2. Related Art
The plasma display device is a flat panel display device which includes a plasma display panel (PDP), and is expected to be the next generation of large flat panel display devices due to its large screen size. The PDP includes two substrates forming a space therebetween, into which an electric discharge gas is injected, and a plurality of electrodes which are formed between the two opposing substrates and to which a voltage is applied to generate a discharge. In addition, a fluorescent substance with a predetermined pattern is excited by ultraviolet rays generated due to the discharge so that a desired image is displayed on the PDP.
The plasma display panel includes a rear substrate and a front substrate which are disposed opposite to each other. Address electrodes are disposed on a surface of the rear substrate, and a first dielectric layer covers the address electrodes. Barrier ribs formed on the first dielectric layer define discharge cells in a matrix pattern. Each of discharge cells is coated with a fluorescent layer of a predetermined thickness.
The front substrate is a transparent substrate, such as a glass substrate, through which visible rays can permeate, and is coupled with the rear substrate on which the barrier ribs are formed. Pairs of sustain electrodes are formed on a back surface of the front substrate so as to intersect the address electrodes. The pairs of sustain electrodes include X electrodes and Y electrodes, respectively. A transparent second dielectric layer covers the pairs of sustain electrodes, and a protective layer is formed on a back surface of the second dielectric layer.
The plasma display panel includes a plurality of display pixels, and each of the display pixels is formed by a red, green or blue discharge cell according to a fluorescent substance which forms the fluorescent layer. Also, the plasma display panel represents a gray scale by manipulating discharge states of each of the discharge cells.
About 40% of the visible rays radiated from the fluorescent layer are absorbed by the sustain electrodes disposed on the back surface of the front substrate, the second dielectric layer covering the sustain electrodes, and the protective layer, and thus the luminous efficiency of the plasma display panel is low.
Furthermore, when the typical three-electrode surface discharge type plasma display panel displays the same image for a long time, the fluorescent layer is ion-sputtered by charged particles of the discharge gas, resulting in permanent image retention.